1. Field of the Invention
The present invention relates to window glazing used in motor vehicles. More specifically, it relates to forming electrical window defrosters on the window glazing.
2. Description of Related Art
In a window defroster, a busbar is used to distribute electrical current to each grid line of the defroster in an attempt to evenly heat the entire defroster grid. As best shown in FIG. 1, conventional defrosters are formed using screen printing techniques where the busbars are filled or solid rectangular reservoirs integrally formed with the grid lines. However, when forming a defroster using robotic printing mechanisms, rather than screen printing techniques, it is quite difficult to produce the filled rectangular reservoirs of the traditional busbar designs.
A defroster may be formed using robotic printing mechanisms by printing directly onto the inner or outer surface of a panel, or on the surface of a protective layer, using a conductive ink or paste and employing various methods known to those skilled in the art. Such methods include, but are not limited to ink jet printing and automatic dispensing. Automatic dispensing techniques known to those skilled in the art of adhesive application include drip & drag, streaming, and simple flow dispensing. Any of the above techniques are best suited for printing comparatively thin, individual line segments of the grid lines.
In view of the above, it is apparent that there exists a need for an improved window defroster design suited for robotic printing techniques.